None of this is conclusive, so don’t start looking for homes in Colorado and Washington just yet. But the six-year survey found that, on average, marijuana users had better blood sugar control and smaller waists than people who had not. Laboratory studies with mice and rats also suggest that marijuana affects metabolism.

Researchers were quick to point out that there could be any number of competing causes … so it’s still unclear whether marijuana gives people smaller waists or people with smaller waists prefer marijuana. However, if a causal link is established, it could potentially lead to new diabetes treatments in the future.